It is most desirable to provide for a device that can be read on demand or at fixed intervals, to determine the level; for example, percent filled or height, or amount; for example, volume, such as gallons, of liquid in a receptacle, such as oil in an oil tank, in order to determine, for example, the accurate amount of oil being delivered or the amount of oil being used from time to time. There are a wide variety of systems for determining the amount and level of oil in an oil tank; however, such systems typically are quite expensive, particularly where sold with an inventory capability. Other systems require the emptying of the tank for the installation of the system. Some systems are devised merely to notify the user when the oil level in a tank drops to a predetermined low point, so that the tank then may be refilled; however, such systems usually have no inventory capability and are alarm-actuated-type systems. Other systems employ a simple hand-pumped manometer installed on oil tanks which generally are not read regularly, because of the need for a user to go to the tank for a direct reading, to obtain the necessary information, and which pump petrometers or manometers are not wholly accurate. Other systems require the continuous supply of air to a tank, in order to provide for reading, while other systems require the employment of two separate tubes in the oil tank with a continuous or intermittent air supply.
It is, therefore, desirable to provide a system and method for a reasonably priced, easily installed and accurate system and method capable of performing inventory and remotely transmitting this information, either on demand or at periodic timed intervals, to a remote location.